Drainage and other trenches of various sizes and shapes are desirable for numerous applications. For example, manufacturing facilities typically require drainage systems which include trenches formed in the building floors to collect, remove and/or recycle excess water or other liquids. In addition, numerous outdoor industrial and commercial sites, such as large parking lots, airports, roadways, toll plazas and the like require drainage systems, including trenches, to collect and direct rainwater and other liquids to underground storm sewers to prevent flooding and to decrease run-off. Similarly, trenches may be utilized for purposes other than drainage, such as to define a channel or duct through which electrical, optical or other cabling extends.
One method of forming these trenches has included placing and securing a number of precast channel sections in position, such as within a ditch which has previously been formed in the ground. A hardenable composition, such as cement, concrete or the like, is then poured around the channel sections and is allowed to set.
Once the hardenable composition has set, it is normally desirable to finish the trench with an elongate grate covering its open top in order to prevent people from unwittingly stepping in the open trench, to provide a smooth surface for vehicle travel, and/or to prevent relatively large objects from entering the trench and potentially blocking the flow of liquid therethrough in drainage applications or damaging cabling disposed within the trench in other applications. The grate is generally supported by a support surface defined longitudinally along an inner portion of each opposed sidewall of the channel sections. In order to stabilize the grate to prevent the grate from rocking when weight, such as from a passing vehicle, is applied thereto, the support surfaces defined by the opposed sidewalls of the channel sections must be aligned in a common plane during the pouring and setting of the hardenable composition about the channel sections. In addition, if the grate is not properly aligned, the grate and/or the channel itself can be damaged by the resulting movement of the grate. Furthermore, if the grate rocks excessively, the grate may even be dislodged from the channel to expose the trench defined thereby. Accordingly, the alignment of the channel sections in the moldable trench forming composition is important to the construction of a satisfactory trench.
Many drainage and other trenches are formed of a number of channel sections. It is also important to align the adjacent channel sections such that the sidewalls and bottom wall of the trench defined by the adjacent channel sections form continuous surfaces. For drainage applications, fluid will then flow smoothly therethrough and will not pool within the trench.
One common method of securing precast channel sections in an aligned relationship within a preformed ditch includes an anchor, such as that described in U.S. Pat. No. 4,498,807 which issued on Feb. 12, 1985 to Larry E. Kirkpatrick, et al. (hereinafter the “'807 patent”). As illustrated in the '807 patent, an anchor generally includes a pair of downwardly extending, elongated spikes which are held in a parallel, spaced-apart relationship by a generally rectangular crosspiece. The anchor also includes a pair of upwardly extending arms that have a predefined shape which corresponds to and engages the predetermined exterior shape of lower portions of the precast channel sections. For example, each opposed sidewall of the precast channel sections can include an outwardly projecting rib extending longitudinally along lower portions of the channel sections. Correspondingly, upper portions of the arms of the anchor can include inwardly extending tabs which engage the longitudinally extending ribs and secure the anchor to lower portions of the channel sections. Accordingly, the anchor can be attached to a precast channel section and the elongated spikes can be inserted into the ground such that the channel section is held at a fixed position within the preformed ditch. Concrete can thereafter be poured about the channel sections to form the completed trench.
The anchors of the drainage channel system of the '807 patent therefore provide a means to accurately position or place each drainage channel section within the ditch. Although the '807 patent does not disclose a means for positioning adjacent drainage channel sections relative to one another, adjacent drainage channel sections can be aligned such that the side walls and bottom surfaces of the channel sections are contiguous. In one embodiment, the bottom surfaces of the drainage channel sections include a bottom surface which has a predetermined slope to facilitate drainage or fluid flow. According to this embodiment, the anchors of the drainage channel system of the '807 patent can position the individual drainage channel sections in an aligned relationship such that the presloped bottom surfaces are contiguous.
Another device for aligning adjacent drainage channel sections is described in U.S. Pat. No. 5,226,748 to Jörg R. Bärenwald et al., which issued on Jul. 13, 1993 and is assigned to ACO Polymer Products, Inc. (hereinafter the “'748 patent”). The '748 patent describes a clip-type support which engages, clamps and supports the end portions of adjacent drainage channel sections. The clip-type support includes two spaced-apart clip structures and an interconnecting central web. Each clip structure has a predetermined shape which corresponds to and mates with the predetermined exterior shape of the end portions of the adjacent drainage channel sections. In particular, each clip structure includes an elbow which receives and supports an outwardly projecting rib which extends longitudinally along the opposed sidewalls of the drainage channel sections. Thus, the adjacent drainage channel sections can be supported in an aligned relationship by the clip-type device. The center web of the clip-type support also includes a pair of outwardly extending tabs. In addition, the clip-type support includes a number of vertical support rods, each having a first end which extends through apertures defined in a respective outwardly extending tab. Each vertical support rod also includes a second end, opposite the first end, which can be imbedded in the ground to support the drainage channel sections in a predetermined spaced relationship above the bottom of the ditch.
In addition to being positioned in an aligned relationship, it is important that the adjacent channel sections be urged together and interlocked. For drainage applications, for example, this interlocking minimizes fluid leakage between adjacent drainage channel sections and escape from the trench. This is normally accomplished manually by careful checking of individual channel sections as they are placed on the individual supports. However, this is a time consuming process requiring substantial attention to detail, and it is easy to accidentally move a previously aligned channel section as a later channel section is being adjusted. In a like fashion, previously aligned channel sections can move or shift while the hardenable composition is poured about the channel sections.